The Problem
A stolen laptop with an unencrypted SSD is trivial to read—pull the drive, plug it into another PC, copy everything. BitLocker scrambles the whole volume so Windows only boots when the key is available (TPM + PIN, password, or recovery key). Home users on Windows 11 Home get Device encryption instead on many OEM PCs; this guide focuses on BitLocker in Pro/Enterprise/Education.
Before You Start
- Windows 11 Pro, Enterprise, or Education (Home: check Settings → Privacy & security → Device encryption toggle).
- TPM 2.0 enabled (most Windows 11 PCs already are—see enable TPM for upgrade if BIOS disabled it).
- Save the recovery key somewhere that is not only on the encrypted drive (Microsoft account, printout, employer portal).
The Fix: Encrypt the System Drive (C:)
Step 1: Open BitLocker Settings
- Settings → Privacy & security → Device encryption, or search Manage BitLocker.
- Or:
Win + R→control /name Microsoft.BitLockerDriveEncryption.
Step 2: Turn On BitLocker for C:
- Click C: → Turn on BitLocker.
- When prompted to save the recovery key, pick Save to your Microsoft account (personal PCs) or Save to a file on a USB stick you will store safely—not on C: itself.
- Choose how to unlock at startup:
- TPM only — seamless boot on trusted hardware (common on laptops).
- TPM + PIN — stronger; you enter a PIN at boot.
- Password — used more on PCs without TPM.
Step 3: Choose Encryption Mode
- New encryption mode — faster on modern SSDs (AES-XTS).
- Compatible mode — only if you dual-boot older Windows or move the drive to odd hardware.
Step 4: Run the Encryption
Choose Encrypt used disk space only for faster first run on a PC already in use, or Encrypt entire drive for new installs. Click Start encrypting—the PC remains usable; expect hours on large HDDs, less on SSDs.
Encrypt a USB or External Drive
- Insert the drive → File Explorer → right-click the drive → Turn on BitLocker.
- Use a password or smart card (password is typical for USB sticks).
- Save the recovery key the same way as for C:.
Recovery Key: Do Not Lose It
- View keys: https://account.microsoft.com/devices/recoverykey (signed in with the same Microsoft account).
- After firmware/BIOS changes, Windows may ask for the 48-digit recovery key at boot—normal behavior.
Suspend BitLocker for BIOS or Hardware Changes
Manage BitLocker → Suspend protection before motherboard swaps or major firmware updates, then Resume after booting successfully once.
BitLocker vs Selling the PC
Encryption protects data in use; selling the machine still needs a full wipe—follow wipe a PC before selling and turn off BitLocker or let the reset remove keys as part of a factory reset.
Being Asked for the Recovery Key at Every Boot?
A firmware update, a Secure Boot change, or new hardware makes the TPM refuse to release the key, so BitLocker falls back to asking you. That is a separate problem with its own fix—including where to find your key: fix the BitLocker recovery key loop.
Encryption protects a stolen laptop; it does nothing against code running on a machine you are signed into. Pair it with Core Isolation and Memory Integrity and LSA protection, which protect the running system and your stored credentials.
Related guides
Set Up UAC and a Standard User Account in Windows 11
Running as administrator gives every program you open full control of the PC. Set UAC to always notify and move daily use to a standard account without losing anything.
Enable Controlled Folder Access in Windows 11
Controlled Folder Access stops unknown apps writing to Documents and Pictures, blocking ransomware before it encrypts. Turn it on and allow the apps you trust.
Enable Core Isolation and Memory Integrity in Windows 11
Memory Integrity blocks malicious drivers from loading into the Windows kernel. Turn it on, and fix the incompatible driver error that stops it switching on.
Enable LSA Protection and Credential Guard in Windows 11
Stop password-stealing tools reading saved credentials out of memory. Turn on LSA protection on any Windows 11 PC, and Credential Guard on Pro and Enterprise.
Enable Smart App Control and SmartScreen in Windows 11
Smart App Control blocks untrusted apps before they run, and SmartScreen warns on risky downloads. Set both up, and understand why Smart App Control needs a clean install.